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      <td width="400px"><p class="toc level1"><a href="docinfo.html">Document Information</a></p>
<p class="toc level1 tocsp"><a href="gexaf.html">Preface</a></p>
<p class="toc level1 tocsp"><a href="gfirp.html">Part&nbsp;I&nbsp;Introduction</a></p>
<p class="toc level2"><a href="bnaaw.html">1.&nbsp;&nbsp;Overview</a></p>
<p class="toc level2"><a href="gfiud.html">2.&nbsp;&nbsp;Using the Tutorial Examples</a></p>
<p class="toc level1 tocsp"><a href="bnadp.html">Part&nbsp;II&nbsp;The Web Tier</a></p>
<p class="toc level2"><a href="bnadr.html">3.&nbsp;&nbsp;Getting Started with Web Applications</a></p>
<p class="toc level2"><a href="bnaph.html">4.&nbsp;&nbsp;JavaServer Faces Technology</a></p>
<p class="toc level2"><a href="giepx.html">5.&nbsp;&nbsp;Introduction to Facelets</a></p>
<p class="toc level2"><a href="gjddd.html">6.&nbsp;&nbsp;Expression Language</a></p>
<p class="toc level2"><a href="bnaqz.html">7.&nbsp;&nbsp;Using JavaServer Faces Technology in Web Pages</a></p>
<p class="toc level2"><a href="gjcut.html">8.&nbsp;&nbsp;Using Converters, Listeners, and Validators</a></p>
<p class="toc level2"><a href="bnatx.html">9.&nbsp;&nbsp;Developing with JavaServer Faces Technology</a></p>
<p class="toc level2"><a href="gkmaa.html">10.&nbsp;&nbsp;JavaServer Faces Technology Advanced Concepts</a></p>
<p class="toc level2"><a href="bnawo.html">11.&nbsp;&nbsp;Configuring JavaServer Faces Applications</a></p>
<p class="toc level2"><a href="gkiow.html">12.&nbsp;&nbsp;Using Ajax with JavaServer Faces Technology</a></p>
<p class="toc level2"><a href="gkhxa.html">13.&nbsp;&nbsp;Advanced Composite Components</a></p>
<p class="toc level2"><a href="bnavg.html">14.&nbsp;&nbsp;Creating Custom UI Components</a></p>
<p class="toc level2"><a href="bnafd.html">15.&nbsp;&nbsp;Java Servlet Technology</a></p>
<p class="toc level2"><a href="bnaxu.html">16.&nbsp;&nbsp;Internationalizing and Localizing Web Applications</a></p>
<p class="toc level1 tocsp"><a href="bnayk.html">Part&nbsp;III&nbsp;Web Services</a></p>
<p class="toc level2"><a href="gijti.html">17.&nbsp;&nbsp;Introduction to Web Services</a></p>
<p class="toc level2"><a href="bnayl.html">18.&nbsp;&nbsp;Building Web Services with JAX-WS</a></p>
<p class="toc level2"><a href="giepu.html">19.&nbsp;&nbsp;Building RESTful Web Services with JAX-RS</a></p>
<p class="toc level2"><a href="gjjxe.html">20.&nbsp;&nbsp;Advanced JAX-RS Features</a></p>
<p class="toc level2"><a href="gkojl.html">21.&nbsp;&nbsp;Running the Advanced JAX-RS Example Application</a></p>
<p class="toc level1 tocsp"><a href="bnblr.html">Part&nbsp;IV&nbsp;Enterprise Beans</a></p>
<p class="toc level2"><a href="gijsz.html">22.&nbsp;&nbsp;Enterprise Beans</a></p>
<p class="toc level2"><a href="gijre.html">23.&nbsp;&nbsp;Getting Started with Enterprise Beans</a></p>
<p class="toc level2"><a href="gijrb.html">24.&nbsp;&nbsp;Running the Enterprise Bean Examples</a></p>
<p class="toc level2"><a href="bnbpk.html">25.&nbsp;&nbsp;A Message-Driven Bean Example</a></p>
<p class="toc level3"><a href="bnbpl.html"><tt>simplemessage</tt> Example Application Overview</a></p>
<p class="toc level3"><a href="bnbpn.html">The <tt>simplemessage</tt> Application Client</a></p>
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<p class="toc level3"><a href="">The Message-Driven Bean Class</a></p>
<p class="toc level4"><a href="#bnbpp">The <tt>onMessage</tt> Method</a></p>
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<p class="toc level3 tocsp"><a href="bnbpq.html">Packaging, Deploying, and Running the <tt>simplemessage</tt> Example</a></p>
<p class="toc level4"><a href="bnbpq.html#bnbpr">Administered Objects for the <tt>simplemessage</tt> Example</a></p>
<p class="toc level4"><a href="bnbpq.html#bnbps">To Build, Deploy, and Run the <tt>simplemessage</tt> Application Using NetBeans IDE</a></p>
<p class="toc level4"><a href="bnbpq.html#bnbpt">To Build, Deploy, and Run the <tt>simplemessage</tt> Application Using Ant</a></p>
<p class="toc level4"><a href="bnbpq.html#bnbpu">Removing the Administered Objects for the <tt>simplemessage</tt> Example</a></p>
<p class="toc level2 tocsp"><a href="gkcqz.html">26.&nbsp;&nbsp;Using the Embedded Enterprise Bean Container</a></p>
<p class="toc level2"><a href="gkidz.html">27.&nbsp;&nbsp;Using Asynchronous Method Invocation in Session Beans</a></p>
<p class="toc level1 tocsp"><a href="gjbnr.html">Part&nbsp;V&nbsp;Contexts and Dependency Injection for the Java EE Platform</a></p>
<p class="toc level2"><a href="giwhb.html">28.&nbsp;&nbsp;Introduction to Contexts and Dependency Injection for the Java EE Platform</a></p>
<p class="toc level2"><a href="gjbls.html">29.&nbsp;&nbsp;Running the Basic Contexts and Dependency Injection Examples</a></p>
<p class="toc level2"><a href="gjehi.html">30.&nbsp;&nbsp;Contexts and Dependency Injection for the Java EE Platform: Advanced Topics</a></p>
<p class="toc level2"><a href="gkhre.html">31.&nbsp;&nbsp;Running the Advanced Contexts and Dependency Injection Examples</a></p>
<p class="toc level1 tocsp"><a href="bnbpy.html">Part&nbsp;VI&nbsp;Persistence</a></p>
<p class="toc level2"><a href="bnbpz.html">32.&nbsp;&nbsp;Introduction to the Java Persistence API</a></p>
<p class="toc level2"><a href="gijst.html">33.&nbsp;&nbsp;Running the Persistence Examples</a></p>
<p class="toc level2"><a href="bnbtg.html">34.&nbsp;&nbsp;The Java Persistence Query Language</a></p>
<p class="toc level2"><a href="gjitv.html">35.&nbsp;&nbsp;Using the Criteria API to Create Queries</a></p>
<p class="toc level2"><a href="gkjiq.html">36.&nbsp;&nbsp;Creating and Using String-Based Criteria Queries</a></p>
<p class="toc level2"><a href="gkjjf.html">37.&nbsp;&nbsp;Controlling Concurrent Access to Entity Data with Locking</a></p>
<p class="toc level2"><a href="gkjia.html">38.&nbsp;&nbsp;Improving the Performance of Java Persistence API Applications By Setting a Second-Level Cache</a></p>
<p class="toc level1 tocsp"><a href="gijrp.html">Part&nbsp;VII&nbsp;Security</a></p>
<p class="toc level2"><a href="bnbwj.html">39.&nbsp;&nbsp;Introduction to Security in the Java EE Platform</a></p>
<p class="toc level2"><a href="bncas.html">40.&nbsp;&nbsp;Getting Started Securing Web Applications</a></p>
<p class="toc level2"><a href="bnbyk.html">41.&nbsp;&nbsp;Getting Started Securing Enterprise Applications</a></p>
<p class="toc level1 tocsp"><a href="gijue.html">Part&nbsp;VIII&nbsp;Java EE Supporting Technologies</a></p>
<p class="toc level2"><a href="gijto.html">42.&nbsp;&nbsp;Introduction to Java EE Supporting Technologies</a></p>
<p class="toc level2"><a href="bncih.html">43.&nbsp;&nbsp;Transactions</a></p>
<p class="toc level2"><a href="bncjh.html">44.&nbsp;&nbsp;Resource Connections</a></p>
<p class="toc level2"><a href="bncdq.html">45.&nbsp;&nbsp;Java Message Service Concepts</a></p>
<p class="toc level2"><a href="bncgv.html">46.&nbsp;&nbsp;Java Message Service Examples</a></p>
<p class="toc level2"><a href="gkahp.html">47.&nbsp;&nbsp;Advanced Bean Validation Concepts and Examples</a></p>
<p class="toc level2"><a href="gkeed.html">48.&nbsp;&nbsp;Using Java EE Interceptors</a></p>
<p class="toc level1 tocsp"><a href="gkgjw.html">Part&nbsp;IX&nbsp;Case Studies</a></p>
<p class="toc level2"><a href="gkaee.html">49.&nbsp;&nbsp;Duke's Tutoring Case Study Example</a></p>
<p class="toc level1 tocsp"><a href="idx-1.html">Index</a></p>
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<a name="bnbpo"></a><h2>The Message-Driven Bean Class</h2>
<a name="indexterm-1486"></a><a name="indexterm-1487"></a><p>The code for the <tt>SimpleMessageBean</tt> class illustrates the requirements of a message-driven bean
class:</p>


<ul><li><p>It must be annotated with the <tt>@MessageDriven</tt> annotation if it does not use a deployment descriptor.</p>

</li>
<li><p>The class must be defined as <tt>public</tt>.</p>

</li>
<li><p>The class cannot be defined as <tt>abstract</tt> or <tt>final</tt>.</p>

</li>
<li><p>It must contain a public constructor with no arguments.</p>

</li>
<li><p>It must not define the <tt>finalize</tt> method.</p>

</li></ul>
<p>It is recommended, but not required, that a message-driven bean class implement the
message listener interface for the message type it supports. A bean that supports
the JMS API implements the <tt>javax.jms.MessageListener</tt> interface.</p>

<p>Unlike session beans and entities, message-driven beans do not have the remote or
local interfaces that define client access. Client components do not locate message-driven beans
and invoke methods on them. Although message-driven beans do not have business methods,
they may contain helper methods that are invoked internally by the <tt>onMessage</tt> method.</p>

<p>For the GlassFish Server, the <tt>@MessageDriven</tt> annotation typically contains a <tt>mappedName</tt> element that
specifies the JNDI name of the destination from which the bean will consume
messages. For complex message-driven beans, there can also be an <tt>activationconfig</tt> element containing <tt>@ActivationConfigProperty</tt>
annotations used by the bean.</p>

<p>A message-driven bean can also inject a <tt>MessageDrivenContext</tt> resource. Commonly you use
this resource to call the <tt>setRollbackOnly</tt> method to handle exceptions for a
bean that uses container-managed transactions.</p>

<p>Therefore, the first few lines of the <tt>SimpleMessageBean</tt> class look like this:</p>

<pre>@MessageDriven(mappedName="jms/Queue", activationConfig =  {
        @ActivationConfigProperty(propertyName = "acknowledgeMode",
                                  propertyValue = "Auto-acknowledge"),
        @ActivationConfigProperty(propertyName = "destinationType",
                                  propertyValue = "javax.jms.Queue")
    })
public class SimpleMessageBean implements MessageListener {
    @Resource
    private MessageDrivenContext mdc;
    ...</pre><p>NetBeans IDE typically creates a message-driven bean with a default set of <tt>@ActivationConfigProperty</tt>
settings. You can delete those you do not need, or add others. <a href="#gjkoh">Table&nbsp;25-1</a>
lists commonly used properties.</p>

<a name="gjkoh"></a><p class="caption">Table&nbsp;25-1 <tt>@ActivationConfigProperty</tt> Settings for Message-Driven Beans</p><table><col width="50%"><col width="50%"><tr><th align="left" valign="top" scope="column"><p>Property Name</p>

</th>
<th align="left" valign="top" scope="column"><p>Description</p>

</th>
</tr>
<tr><td align="left" valign="top" scope="row"><p><tt>acknowledgeMode</tt></p>

</td>
<td align="left" valign="top" scope="row"><p>Acknowledgment mode; see <a href="bncfu.html#bncfw">Controlling Message Acknowledgment</a> for information</p>

</td>
</tr>
<tr><td align="left" valign="top" scope="row"><p><tt>destinationType</tt></p>

</td>
<td align="left" valign="top" scope="row"><p>Either <tt>javax.jms.Queue</tt> or
<tt>javax.jms.Topic</tt></p>

</td>
</tr>
<tr><td align="left" valign="top" scope="row"><p><tt>subscriptionDurability</tt></p>

</td>
<td align="left" valign="top" scope="row"><p>For durable subscribers, set to <tt>Durable</tt>; see <a href="bncfu.html#bncgd">Creating Durable Subscriptions</a> for information</p>

</td>
</tr>
<tr><td align="left" valign="top" scope="row"><p><tt>clientId</tt></p>

</td>
<td align="left" valign="top" scope="row"><p>For durable subscribers,
the client ID for the connection</p>

</td>
</tr>
<tr><td align="left" valign="top" scope="row"><p><tt>subscriptionName</tt></p>

</td>
<td align="left" valign="top" scope="row"><p>For durable subscribers, the name of the
subscription</p>

</td>
</tr>
<tr><td align="left" valign="top" scope="row"><p><tt>messageSelector</tt></p>

</td>
<td align="left" valign="top" scope="row"><p>A string that filters messages; see <a href="bnceh.html#bncer">JMS Message Selectors</a> for information, and see <a href="bncgw.html">An Application That Uses the JMS API with a Session Bean</a>
for an example</p>

</td>
</tr>
<tr><td align="left" valign="top" scope="row"><p><tt>addressList</tt></p>

</td>
<td align="left" valign="top" scope="row"><p>Remote system or systems to communicate with; see <a href="bnchp.html">An Application Example That Consumes Messages from a Remote Server</a> for an
example</p>

</td>
</tr>
</table>

<a name="bnbpp"></a><h3>The <tt>onMessage</tt> Method</h3>
<a name="indexterm-1488"></a><a name="indexterm-1489"></a><a name="indexterm-1490"></a><p>When the queue receives a message, the EJB container invokes the message listener
method or methods. For a bean that uses JMS, this is the
<tt>onMessage</tt> method of the <tt>MessageListener</tt> interface.</p>

<p>A message listener method must follow these rules:</p>


<ul><li><p>The method must be declared as <tt>public</tt>.</p>

</li>
<li><p>The method must not be declared as <tt>final</tt> or <tt>static</tt>.</p>

</li></ul>
<p>The <tt>onMessage</tt> method is called by the bean&rsquo;s container when a message has
arrived for the bean to service. This method contains the business logic that
handles the processing of the message. It is the message-driven bean&rsquo;s responsibility to
parse the message and perform the necessary business logic.</p>

<p>The <tt>onMessage</tt> method has a single argument: the incoming message.</p>

<p>The signature of the <tt>onMessage</tt> method must follow these rules:</p>


<ul><li><p>The return type must be <tt>void</tt>.</p>

</li>
<li><p>The method must have a single argument of type <tt>javax.jms.Message</tt>.</p>

</li></ul>
<p>In the <tt>SimpleMessageBean</tt> class, the <tt>onMessage</tt> method casts the incoming message to
a <tt>TextMessage</tt> and displays the text:</p>

<pre>public void onMessage(Message inMessage) {
    TextMessage msg = null;

    try {
        if (inMessage instanceof TextMessage) {
            msg = (TextMessage) inMessage;
            logger.info("MESSAGE BEAN: Message received: " +
                msg.getText());
        } else {
            logger.warning("Message of wrong type: " +
                inMessage.getClass().getName());
        }
    } catch (JMSException e) {
        e.printStackTrace();
        mdc.setRollbackOnly();
    } catch (Throwable te) {
        te.printStackTrace();
    }
}</pre>
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